Idol of the Deep King // Sovereign's Macuahuitl

A Shock that refuses to leave. Cast at flash speed, the front face enters, throws two damage at any target, and stays on the battlefield as an artifact rather than heading to the graveyard the way a burn spell would. That persistence is the entire point: you collect instant-speed removal now and keep the artifact around as fuel for a slower turn, where the craft cost (exile this artifact plus another artifact you control or from your graveyard, only as a sorcery) flips it into an Equipment that snaps onto a creature you control on entry and grants +2/+0. Requiring a second artifact to reach the back half is the tax that stops the front half from being pure upside; the transformation asks for a board already stocked with cheap artifacts to feed rather than a deck running this alone.

Flash is what lifts the removal above a plain Shock. Holding three mana to answer a threat at the end of an opponent's turn or ambush an attacker mid-combat is a live line, and unlike a spell that resolves and clears the stack, it leaves a permanent behind for later. The craft ability converts that stranded artifact into a repeatable attach-and-swing tool. The design wants two different game states across its lifetime, an early tempo turn and a slower grind, and pays out at both.